I know Twi used some reading technique some times that does not work on my Oric, I cannot play Pulsoids, but I am not sure if this is due to incorrect setting of the I/O port B in the AY (register 7, bit 6), because the symptoms are the same as I had in 1337 when I inadvertently set it to 0 (input) when stopping sound: it worked perfectly in Oricutron, but not in a real machine.

I used Oricutron's debugger and the bit seems to be set, but I don't know if the difference between the emulator and the real machine is that this bit is always set (even when you try to set it to zero) or that its status is ignored.

I could create a test program, I know, but if someone tried this in their Oric and it worked, then I can discard this and assume it is related to mine only

In the audio department, there are things that work on some Oric and not some other, mostly related to a specific feature of the VIA.
At the end of of Quintessential there is a black and white scroller with noise effect, it has some sample sound playing at the same time, but it does not work on all machines.

Yeah, I know Dbug. I never understood why samples do not work on my Atmos, but most intriguing is why the keyboard does not work in Pulsoids.

The thing here is that I can boot the disk and launch the editor, but from there I cannot do anything because the keyboard does not respond. I think that older versions did work (though I'd have to double check), so I was wondering if it is because a change in the way the keyboard is handled (strange) or a bug where a 0 is written to the I/O bit when setting all the registers to initial values (quite possibly - I had exactly that bug in 1337 in the StopSound routine).

The latter was not detected with Oricutron or Euphoric, because they seem not to emulate this behaviour. Looking with the debugger in Oricutron, the bit is not set to 0, but I am not sure if the emulator keeps it as 1 or simply ignores the value.

Does it work with other samples - Soundtracker or Rhetoric disks, for example?
Is it working from disk? Sometimes you get odd problems like tape not loading when disk drive is in.

I wasn't sure at first what IM Music was so never got round to trying this with my Atmos(es) but I know Pulsoids works fine on all the systems I've tried it on. I think Twi reduced samples down to 4bit or something, if that makes any difference(?)

Do you have a disk with the Microman music sample (sometimes describes as Rob Hubbard music. I've heard it said it was the theme to Warhammer, or that it was Micro Maniac or that it came from a Monty Mole game- I've not been able to find examples of these that match the tune.)

On tape-based experiences, IIRC some of my computers didn't like Zip and Zap for instance: it seemed to load fine but when starting a game it began crashing. I noticed that while testing Novalight, but I double-checked and it also happened when loading the game at standard speed.
Just in case this could relate to the current discussion.